PCNT is critical for the association and conversion of centrioles to centrosomes during mitosis
PCNT is critical for the association and conversion of centrioles to centrosomes during mitosis
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DOI：
10.1242/jcs.225789
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发表时间：
2019-03-01
影响因子：
4
通讯作者：
Rhee, Kunsoo
中科院分区：
文献类型：
--
作者：
Kim, Jaeyoun;Kim, Jeongjin;Rhee, Kunsoo
中心体由一对中心粒和中心粒周围物质（PCM）组成。我们操纵了PCM关键蛋白PCNT的表达，并研究了PCM在有丝分裂过程中对中心粒行为的影响。PCNT的缺失对间期中心体影响不大。然而，PCNT缺失的有丝分裂细胞中的中心粒过早分离并频繁扩增，表明有丝分裂过程中中心粒被PCNT限制在纺锤极内。在有丝分裂过程中，PCNT的特异性裂解是中心粒分离所必需的。我们观察到，当PCNT的不可切割突变体被移除或PCNT被TEV蛋白酶人工切割时，氧化石墨烯期的中心粒分离延迟。此外，子中心粒只有在经历有丝分裂退出和特异性PCNT切割后才能转化为母中心粒。基于这些结果，我们提出一个中心粒对在进入有丝分裂时脱离，但在整个有丝分裂过程中仍与周围的PCM蛋白相关。在有丝分裂结束时，PCNT的特异性裂解诱导PCM解体。结果，子中心粒与母中心粒分离，转化为年轻的母中心粒。
A centrosome consists of a pair of centrioles and pericentriolar material (PCM). We manipulated expression of PCNT, a key PCM protein, and investigated roles of PCM in centriole behavior during mitosis. Deletion of PCNT had little effect on interphase centrosomes. However, centrioles in PCNT-deleted mitotic cells prematurely separated and frequently amplified, revealing that centrioles are limited within the spindle poles by PCNT during mitosis. It is known that specific cleavage of PCNT is necessary for centriole separation during mitotic exit. We observed delayed centriole separation in the GO phase when a non-cleavable mutant form of PCNT was removed or when PCNT was artificially cleaved by TEV protease. Furthermore, a daughter centriole converts to a mother centriole only after experiencing both mitotic exit and specific PCNT cleavage. Based on these results, we propose that a centriole pair disengages upon entering mitosis but remains associated with the surrounding PCM proteins throughout mitosis. During mitotic exit, specific cleavage of PCNT induces PCM disintegration. As a result, a daughter centriole separates from the mother centriole and converts to a young mother centriole.